In the most extreme case consider where you enter a wide but short run at the top from one side of it instead of from the middle, and the run ends at a chair in the middle.

If you take a high line to the centre of the run and then go pretty much straight down it then you will ride down the fall line and spend generally equal time on both edges. If you ride in a mostly straight line from the entrance to the fall line you are crossing the fall line and you arent riding the fall line but more across it so you will spend most of your time on one edge, which in extreme cases is kind of boring, sometimes its more fun to get to the middle of the run rather than just getting pushed to the centre as you go down one side.

A friend of mine pointed out to me that Whistler Mountain's runs are more often cut across the fall line as opposed to Blackcomb. I'd never thought about this but I did notice it next day, and I did prefer to ride some runs on blackcomb where I could ride the fall line intead of having to mostly go across it.

It's certainly worth looking ahead at the shape of the hill to see where the fall line changes to choose your route.

As far as above/below the fall line I'm not sure about this, other that that when carving your normally switch edges as your board's nose crosses the fall line, ie. when it's pointing down at the max angle of the hill. If you switch edges early you are I guess turning above the fall line, and then you carve across it.

A friend of mine pointed out to me that Whistler Mountain's runs are more often cut across the fall line as opposed to Blackcomb. I'd never thought about this but I did notice it next day, and I did prefer to ride some runs on blackcomb where I could ride the fall line intead of having to mostly go across it.

It's certainly worth looking ahead at the shape of the hill to see where the fall line changes to choose your route.
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A bud that skis w/b said that w side was kind of unplanned though when they were planning b side, they did a good topo survey and put the runs down the fall line. btw he thinks the w side is faldkfjdotu up.

A bud that skis w/b said that w side was kind of unplanned though when they were planning b side, they did a good topo survey and put the runs down the fall line. btw he thinks the w side is faldkfjdotu up.

I think snowboarders suffer on it even more, my friend's wife much prefers blackcomb, she says whistler is really not optimized for snowboarders, both in terms of the runs and the traverses.

I've never heard any movement described in terms of "above the fall line." What on earth could that possibly mean? "Down the fall" line and "across the fall line" and "double fall line" I understand.

Yes, when doing serious carving with big complete C-shaped turns you often intentionally switch edges while going across the fall line. For a brief time, you are hanging out in space with your center of mass *below* the board and you are carving the downhill edge. (I absolutely love the feeling of riding the downhill edge and even pushing it hard. It takes a leap of faith in gravity, your skill, and equipment.)

What Lamps describes as runs that are cut across the fall line are often described as having a "double fall line" -- the general route of the trail does not match the fall line. In my earlier years riding I had major problems learning to ride these kinds of trails. I'm regular, so think of a trail that in addition to going generally downhill, is cut such that it also slopes off to the right. I hated toe-side turns on this kind of trail because coming out of the turn I'd be barreling straight for the trees.

This picture series is intended to illustrate an advanced move called a "cross-through" turn (don't worry about that yet), but we can use it to discuss a bunch of things. Notice how the rider in pictures 1, 2, and 3 is completing a carved toeside turn. The toe edge is the uphill edge and he's traveling across the fall line. In picture 4 his base is flat across the hill (actually he's off the ground). In 5 he switches edges to start a heelside turn. The heel edge is the downhill edge at the start of this turn. Look real closely. He's traveling at us (across the fall line) with the mass of his body *below* his board. Cool, no?* In 6, he's trucking around the turn on his heel. In 7, he's moving downhill again and aiming the board down the fall line through the turn. (We can anticipate what happens next: as he completes the heelside turn it will be the uphill edge then he'll switch to toeside going away from us toward the trees.)

*If you try to ride *down the fall line* on your downhill edge, you will trip over that downhill edge and fall hard. This rider is riding that downhill edge *across* the fall line. In other words, if you're riding in the position that the guy in picture 5 is riding in, and you're traveling down the hill (and not across), you won't be doing that for long -- you're going to trip over that downhill edge.

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